Normalize A Database To 3nf

A simple step-by-step way to normalize the table to 3NF Step 1: Make the following questions: Does the question on the table have duplicate groups? No: It's 1NF. Yes: Because that is unusual, you can delete duplicate groups and do it with 1NF.  Step 2: The primary key contains only one column. Yes - the table is already on 2NF. Please do not ask next question. There are some keys for determining values, but not all, for non - key columns.

Since the 1NF standard is satisfied by defining all the primary and foreign keys of each entity, Riordan's inter-enterprise database proposal is standardized to 3NF. There are no duplicate groups, and all attributes of each entity are checked to ensure that no data is duplicated. Finally, all values ​​for each entity depend on the primary key. Since E - R resolves partial dependencies, it is not currently available, so 2NF is implemented. 3NF is implemented when all noncritical attributes are functionally dependent only on the primary key. For example, each attribute in the VENDORS table is functionally dependent on the primary key of VendorID. This process was conducted for each entity of 3NF ERD.

Third Normal Form (3NF) - If the relationship is in the second paradigm and each non-critical attribute is functionally completely dependent on the entire primary key, not the other non-critical attribute, that relationship will be in the third paradigm Yes. In other words, there is no transitive dependency between attributes. Transitive dependencies can be explained as follows. "When A decides B, B determines C and A determines C" Fourth normal form (4NF) - There should be no trivial multivalued dependency in the relationship. To move from BCNF to 4NF, delete all independent multi-valued components of the primary key for the two new parent entities. For example, if an employee can have many skills and a large number of families, they are duplicates and are independent of each other, so skills and related information are moved to separate tables